الفهرس 
Chapter 1 Introduction and Literature ReviewOnly 14 pages are availabe for public view
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Abstract
For the past three decades, a considerable amount of research has
advanced our understanding of the effect of time delays on the behavior
of dynamical systems. These delays, which may either exist within a
system’s internal states or are introduced through closed-loop feedback,
produce complex dynamic responses that can deteriorate a controller’s
performance. Time delay often appears in many control systems either in
the state, in the control input, or in the measurements. Time delay
commonly exists in various engineering systems because of the finite
speed of information processing and it is a source of performance
degradation and instability. Therefore the stability, performance analysis
and the control of systems with time delays are both theoretically and
practically important. Vibrations and dynamic chaos are undesired
phenomenon in structures. They may cause disturbance, discomfort,
damage and destruction of the system or the structure. For these reasons,
money, time and effort are spent to get rid of both vibration and noise or
chaos or to minimize them. Vibration control is an important engineering
problem and many techniques for both active and passive vibration
absorption have been developed. The use of active control with time
delay improves the behavior of the system at worst resonance cases.
The objectives of this work are to suppress the vibration of different
non-linear dynamical systems simulating their practical cases via time
delay controllers. The first model is represented by a two-degree-offreedom
system consisting of the main system and the controller. The
second model is the coupled nonlinear differential equations representing
the vibration of a nonlinear spring pendulum simulating ship pitch-roll
motion (two-degree-of-freedom) subjected to different or mixed
excitation forces.
Abstract
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These models are subjected to different types of multi excitations forces
which represented as the following:
1- In chapter two we dealt the non-linear beam system subjected to
multi-external excitation forces or multi-parametric excitation
forces or multi-tuned excitation forces. Some results are published
[41, 42]. Other results are submitted for publication [43].
2- In chapter three we dealt the non-linear control of a beam system
subjected to mixed multi excitation forces. Some results are
submitted for published [44-47].
3- In chapter four we studied the non-linear spring pendulum system
subjected to multi-external excitation forces or multi-parametric
excitation forces or multi-tuned excitation forces. Some results are
submitted for publication [48-50].
4- In chapter five we studied the non-linear spring pendulum system
subjected to mixed multi excitation forces. Some results are
submitted for published [51-54].
The multiple time scale perturbation technique is applied throughout to
get a solution to the second order approximation. The stability of the
system is investigated numerically applying both phase-plane and
frequency response functions using MATLAB 7.0 and MAPLE 11.0
programs. The effects of the different parameters of the controller on
system behavior are studied numerically. All worst reported resonances
cases are studied numerically, applying Rung-Kutta fourth order method.
Time delay controller is an effective tool for vibration suppression as the
ordinary one but within a specified range of time delay. Comparison with
the available published work is reported.